Thirty Years' War

The Thirty Years War was a war waged in Central Europe and the Low Countries between 1618 and 1648. Originating as a civil war between Catholic and Protestant Bohemian nobles that culminated in the 1620 Battle of White Mountain, it later spread to the rest of Europe as Protestant countries (later joined by Catholic France) fought the Catholic (Habsburg Empire-ruled) countries. It ended in the Peace of Westphalia, restoring the status quo, with both sides agreeing to the 1555 Peace of Augsburg (the cuius regio, cuius religio treaty).

Background
Religious faith may begin with the individual conscience, but it seldom ends there. In 16th-century Europe, it was also at the heart of social and cultural existence.

Jostling for Position
Religion was increasingly the centre of political life, especially once the Protestant Reformation had opened up the possibility of difference of belief. In 1562 Catholic opposition had plunged France into civil war during the Wars of Religion, and fuelled the hatreds that resulted in the Dutch Revolt.

Faith Divide
Feelings ran high in the home of the Reformation. In 1517 Martin Luther had made his famous stand in Wittenberg. Germany, within the Holy Roman Empire actually a patchwork of principalities, duchies, and other small states, was soon divided along religious lines. Serious conflict was avoided when, at the Peace of Augsburg in 1555, the principle of cuius regio, cuius religio ("whose region, whose religion") was agreed and regional independence cemented. If the ruler was Catholic, then that was the state's religion; if the ruler was Protestant, than so were his people. As time went on, impatience grew over what appeared to be an unresolved issue. Emperor Rudolf II seemed to be storing up trouble with his tolerant attitude.

War
One of Europe's most tragic episodes began in farce, when Protestant nobles in Bohemia hurled two imperial governors, accused of violating Protestants' rights, from a high window into a heap of horse manure. The officials in the Town Hall had been acting on behalf of the empire and the Church, and this "Defenestration of Prague" symbolized the Protestants' defiance. Rocked by the Reformation, the empire had drawn strength from the Counter-Reformation and there were fears that Catholicism would again be enforced. While the Habsburg emperor, Matthias, remained ruler of Upper and Lower Austria and Holy Roman Emperor until his death in 1619, in 1617 his nephew, Ferdinand, had been elected King of Bohemia by the Bohemian Diet in a move that was engineered by loyalist Bohemian grandees to ensure a fluid Habsburg succession to the aged Matthias's titles. Ferdinand's aggressive Catholic devotion was well known but the Bohemian elites assumed that he would respect their religious privileges.

The Conflict Spreads
Instead, Ferdinand instantly sought to change things in Bohemia in favour of the Catholics - the result was the Defenestration and open rebellion against Habsburg authority. The Protestant rebels looked to their religious allies for help, and especially to the Calvinist ruler of the Palatinate, Elector Frederick V. Frederick was the leader of the Protestant Union, a military alliance of the radical Protestant States in Germany set up by his father in 1608. In 1619 Matthias died; Ferdinand inherited his remaining titles and was elected as the Holy Roman Emperor, Ferdinand II. Despite this development, the Bohemian rebels declared Ferdinand deposed and elected Frederick V to his place as ruler of Bohemia. Ferdinand responded by preparing his military forces and looking to the support of his Habsburg cousin in Spain, Philip III, and the Catholic League, composed of German states under the leadership of German states under the leadership of Bavaria, which had been set up in 1609 to counter the Protestant Union. In late 1620, at the battle of White Mountain just outside Prague, a united Catholic army crushed Frederick's forces, deposed him, and put down the revolt. Frederick fled into exile, his own territories in Germany held by the victorious Catholic forces, and Habsburg authority and Catholicism were imposed in Bohemia. But this just the start, not the end, of hostilities, as with religious principles at stake in both the Holy Roman Empire and across a wider European stage, a variety of powers and interests were to get involved.

In 1626, Christian IV of Denmark took up the Protestant banner, but he was worsted in successive engagements with the army of the Catholic League led by Count Tilly and the emperor's army, created, funded, and led by Albrecht von Wallenstein. Wallenstein aroused fear and outrage among the rulers of the Holy Roman Empire. Although without a princely title, his virtually private army had carried the emperor's power across Germany and to the Baltic coasts, and had been funded by a wave of transfers and confiscations of territory into his hands. Eventually his power was to unnerve the emperor himself - by the late 1620s Wallenstein had an army 60,000 strong. But for the moment though, he was the emperor's greatest asset. Wallenstein's defeat of Denmark took that country out of the war, while Sweden's Gustavus Adolphus stepped up to lead the Protestants.

The Peace of Prague
Gustavus Adolphus won a resounding victory at the first Battle of Breitenfeld on 17 September 1631. The following year, Wallenstein's men were mauled at Lutzen by the Swedes, but Gustavus Adolphus was killed. Without him the Swedes faltered and were beaten at Nordlingen in 1634. The emperor had the upper hand again. He imposed a truce, followed by a general German peace at Prague, in 1635.

The German princes, Protestant and Catholic, were war weary and alienated by Sweden's military policies. They accepted a settlement that moderated the emperor's tough religious demands. This settlement did not please Catholic France, however. Cardinal Richelieu, King Louis XIII's chief minister, had grown uneasy at the thought of the Habsburgs being so firmly established in Germany and Spain. So France declared war on both Spain and the empire, soon invading the Spanish Netherlands and imperial territories along the Rhine, but they were repelled. Spanish and German armies cut through Picardy, Burgundy, and Champagne. The Habsburgs were also weakened by Dutch victories at sea and an uprising in Portugal in 1640.

Concentrating its forces in North Germany, Sweden regrouped before winnind decisively at the Second Battle of Breitenfeld in 1642. Spain's tercios were massacred at Rocroi in France the year after, by France's Duc d'Enghien and his use of cavalry and artillery.

Gradually, the fighting eased, and in 1648 the Treaty of Westphalia was signed. After 30 years of battle and the loss of millions of lives, the two sides had effectively returned to the accommodation acceded at the Peace of Augsburg in 1555: both Catolic and Protestant rulers agreed to differ.

Aftermath
The Thirty Years War had been both a crucible for lasting hatreds and a useful laboratory for the testing and development of new technology and tactics.

Trouble at Home and with Spain
In France the easing of external threats allowed domestic discontents to boil over in the popular rebellion known as the Fronde. Spain - still at war with France - took the opportunity to take back Catalonia and other captured territories. This injected new acrimony into the Franco-Spanish War, which went unresolved until 1659.

Tactical Advances
Tactics witnessed in the Thirty Years War were exploited by France's Louis XIV in the series of wars he fought from 1661. They were also used in England in Cromwell's war with the Stuart Crown.